Field
Embodiments described herein relate generally to a LDO voltage regulator and a power receiving apparatus.
Background Art
Some conventional LDO voltage regulators have a current detecting transistor for detecting the output current in addition to the output transistor. In operation of the LDO voltage regulator, the detecting transistor and the sensing transistor are completely turned on and serve as switches.
In general, in order to use both the output transistor and the detecting transistor in the LDO voltage regulator that passes a high current, the resistance ratios have to perfectly agree with each other to ensure pair properties. However, pair properties cannot be ensured because of the large size of the output transistor, so that it is difficult to use both the output transistor and the detecting transistor in the LDO voltage regulator.
Depending on the size of the output transistor, the current density may vary, and the resistance of the device may be variable.
Therefore, accurate current detection cannot be achieved if the input voltage varies, and the drain-source voltage of the output transistor significantly varies.